Pyun was a military brat and lived on bases around the world until his father settled in Hawaii. Pyun went to school in Kailua, a small town located on the windward side of Oahu. Pyun's first 8mm and 16mm movies were made in Kailua and he credits living in foreign countries and growing up in Hawaii as strong influences on his filmmaking style.
While in high school, Pyun worked at a number of production houses in Honolulu before receiving an invitation by the Japanese actor, Toshiro Mifune, to travel to Japan for an internship. Initially Pyun was to intern on the Akira Kurosawa film, Dersu Uzala, which was to star Mifune but the actor decided not to do the film and instead Pyun found himself working on a Mifune TV series under the tutelage of Kurosawa's Director of Photography, Takao Saito (Red Beard).
Pyun returned to Hawaii and began working as a commercial film editor at KGMB in Honolulu and edited commercials for agencies such as Bozell Jacobs and Leo Burnett. After several years as an editor, Pyun moved to Los Angeles to become a feature film director.
Pyun's first film, The Sword and the Sorcerer remains his highest grossing, eventually earning $36,714,025 in the United States. Opening on April 30, 1982 it grossed $4,100,886 which ranked the film second that week in America. Richard Lynch received the Best Supporting Actor Saturn Award for his performance as Cromwell. During the production of the film stuntman Jack Tyree was killed while doing a high fall stunt at Griffith Park in Los Angeles. While performing a 78-foot fall in heavy costume and makeup, Tyree struck his airbag off center, resulting in a fatal impact.
With the success of The Sword and the Sorcerer, Pyun was attached to several science fiction projects in 1984 including Total Recall, to be produced by Dino DeLaurentiis at Universal Pictures, screenplay based on the Philip K. Dick story written by Ronald Shusett (Alien). At the time, William Hurt, was attached to star.
His second film, Radioactive Dreams, was awarded the Golden Raven at the 5th Brussels International Fantastic Film Festival in 1987. "Radioactive Dreams" recently screened at Exhumed Films' 2013 eX Fest.
Pyun's career took a more mainstream turn with the thriller Dangerously Close, and the romantic adventure film, Down Twisted, starring Carey Lowell, Charles Rocket, and Courteney Cox.
In the late 1980s, Pyun made Alien from L.A., featuring supermodel Kathy Ireland; the film was later mocked on an episode of Mystery Science Theater 3000. This episode was released on DVD in March 2013.
Pyun's Cyborg opened as the fourth highest-grossing film in America on April 7, 1989. It eventually grossed $10,166,459 in the United States. 22 years after making "Cyborg," Pyun released his director's cut in 2011. A Metro-Goldwyn-Mayer re-release on Blu-ray followed in October 2012.
In 1989, Pyun made Deceit, and Captain America. A director's cut of Captain America was released in May 2011.
In the early 1990s, Pyun made Nemesis with Olivier Gruner and Thomas Jane; Brainsmasher... A Love Story followed in 1993 with Teri Hatcher and Andrew Dice Clay; and Mean Guns with Christopher Lambert and Ice-T in 1997.
In June 1991, Pyun's film Kickboxer 2, written by David Goyer (Ghost Rider, Blade, The Dark Knight), opened in theaters to mixed reviews.
Other 1990s films include: Knights with Kris Kristofferson, Kathy Long and Lance Henriksen; "Dollman" starring Tim Thomerson as a 13 inch tall Dirty Harry type cop from another planet. Jackie Early Haley played the villain; Raven Hawk with Rachel McLish and William Atherton; Spitfire with Henriksen, Sarah Douglas, Tim Thomerson and Kristie Phillips; Hong Kong '97 with Robert Patrick and Ming-Na Wen; Adrenalin: Fear the Rush with Christopher Lambert and Natasha Henstridge; Post Mortem with Charlie Sheen; Crazy Six with Rob Lowe, Mario Van Peebles and Burt Reynolds; Omega Doom with Rutger Hauer and Shannon Whirry; Arcade with Megan Ward, Seth Green, Peter Billingsly and John Delancie. Pyun also made his only episodic TV work to date for the NBC/Columbia Tri-Star show The Fifth Corner with Alex McArthur, Kim Delaney and James Coburn.
Pyun directed and produced Ticker for Artisan Entertainment in May 2000, which featured Steven Seagal, Tom Sizemore, Dennis Hopper, Jaime Pressly, Nas and Ice-T plus Chilli of the R&B group TLC. In 2002 it was among five films honored for sales by the Video Software Dealers Association in the category of Direct-To-Video/Limited Release By An Independent Studio.
In 2004 Pyun went to the U.S. territory of Guam and, along with film producer John Laing, convinced the Guam government to put up an $800,000 loan guarantee to finance their film Max Havoc: Curse of the Dragon. In his effort to convince Guam officials to approve the loan guarantee, Pyun told them that he and his producer (Laing) had a "sterling financial record" and that neither he nor John Laing had ever defaulted on a loan. In 2006 Laing defaulted on the loan, and Guam lost its guarantee. Laing blamed Pyun for the failure of the film. An out of court settlement was reached between John Laing and the Guam Economic Development Authority in May 2012 but up until October 2012 Laing has not honored the terms of that settlement. In late 2012 GEDA Administrator Karl Pangelinan reported Laing had made a $75,000 payment on the balance of the settlement amount and the balance outstanding was $75,000. GEDA officials confirmed the final payment was made in February 2013 bringing the matter to a close. Pyun was not involved in any of the legal litigation between GEDA and Laing.
In September 2008, Pyun began production on Tales of an Ancient Empire. Shooting began on October 12, 2008. The film premiered at Louisville, Kentucky's Fright Night Film Fest. The film was eventually released by Lions Gate Films in January 2012 and stars Kevin Sorbo, Michael Paré, Melissa Ordway and Ralf Moeller.
Pyun's film Road to Hell won the Best Picture award at the Yellow Fever Independent Film Festival in Belfast in 2011. Later in 2012, it opened the PollyGrind Film Festival in Las Vegas where it won Best Fantasy Film, Best Actor, Best Actress, Best Supporting Actress, Best Song, Best Use of Songs, Best Use of Music, Best Visual Effects, Best Screenplay, and the Newcomer Award.
In late 2013, Pyun announced he had multiple sclerosis. In March 2014, Pyun's health had improved enough for him to film The Interrogation of Cheryl Cooper.2005 - Golden Unicorn Award for lifetime achievement at the Estepona International Film Festival of Fantasy and Horror.
2011 - Induction into the B-movie Hall of Fame at the B-Movie Celebration.
2012 - Lifetime Achievement-Filmmaker of a Different Breed Award at the PollyGrind Film Festival.
2013 - Groundbreaker Award - BUT FILM FESTIVAL (Breda, Netherlands)
2013 - Indie Genre Spirit Award - Buffalo Dreams Fantastic Film Festival
The Sword and the Sorcerer (1982)
Radioactive Dreams (1985)
Dangerously Close (1986)
Down Twisted (1987)
Alien from L.A. (1988)
Captain America (1990)
Kickboxer 2 (1991)
Brainsmasher... A Love Story (1993)
Kickboxer 4 (1994)
Hong Kong 97 (1994)
Nemesis 2: Nebula (1995)
Omega Doom (1996)
Nemesis 3: Prey Harder (1996)
Raven Hawk (1996)
Nemesis 4: Death Angel (1996)
Mean Guns (1997)
Urban Menace (1999)
The Wrecking Crew (2000)
Max Havoc: Curse of the Dragon (2004)
Left for Dead (2007)
Road to Hell (2008)
Tales of an Ancient Empire (2010)
The Interrogation of Cheryl Cooper (2014)
Interstellar Civil War (2017)
Devil Girl (2007)